Spring



C. CAMPBELL Feb. 23, 1965 SPRING Filed Sept. 13, 1963 United States Patent F 3,170,448 SPRING Colin Campbell, Racine, Wia, assignor t0 Walker Manufacturing Company, Racine, Wis., a corporation of Delaware Filed Sept. 13, 1963, Ser- No. 308,839 Claims. (QB. 123-119) This invention relates generally to crankcase ventilation systems, and more particularly, to a flame stop adapted to be operatively mounted in a blowby passage extending between the crankcase and the air intake system of an internal combustion engine. 7

It has been the practice in crankcase ventilation systems to provide means for extinguishing or quenching the induction backfiring of blowby gases as they are communicated from the crankcase to the combustion air intake system. Such flame quenching means, or flame stops, must be capable of effectively precluding flame propagation, while at the same time, permitting sufiicient flow of blowby gases to the air intake system. A frequent objection to flame stops heretofore known and used has been directed towards their inability to prevent residue and contaminants within the crankcase emissions from accumulating thereon, and thus seriously limiting the desired flow of blowby gases to the air intake system. Accordingly, the present invention is directed towards a novel flame stop adapted to be operatively mounted within the blowby passage of a crankcase ventilating system, and which is operable to move slightly within the blowby passage with normal engine vibrations, thus preventing the aforementioned crankcase residue from adhering to and accumulating on the flame stop to limit the desired fiow of blowby gases.

It is therefore a primary object of the present invention to provide an improved flame stop for a crankcase ventilation system which is capable of effectively precluding flame propagation, while at the same time, permitting a sufficient flow of blowby gases to the engines air intake system.

It is another object of the present invention to provide an improved flame stop adapted to eifectively prevent crankcase residue and contaminants from accumulating thereon and thus limit the desired flow of blowby gases to the air intake system.

It is still another object of the present invention to provide an improved flame stop of an extremely simple design that can be easily assembled and economically manufactured.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawing, wherein:

FIGURE 1 is a side elevational view, partially in section, of a preferred embodiment of the flame stop of the present invention in operative association with a schematic representation of a conventional internal combustion engine; and

FIGURE 2 is an enlarged sectional view of the flame stop illustrated in FIGURE 1, taken within the circle 2 thereof.

Referring now to FIGURE 1, a flame stop 10, in accordance with a preferred embodiment of the present invention, is shown in operative association with an internal combustion engine, generally designated 12, having a crankcase 14 and an oil inlet passage 16 which is covered by an oil filter cap 18, A conventional air cleaner 2 0, having a suitable filter element 22 and an air intake chamber 24, is operatively connected through a carburetion assembly 26 and an intake manifold 28 to the engine 12. A hose-like or tubular conduit 30 extends between the crankcase 14 and the air cleaner fidldgid Patented Feb. 23, 1965 2G to communicate the blowby gases, which accumulate Within the crankcase 14, to the air cleaner 20. A second tubular conduit 32 is connected at one end to the intake manifold 28, and at the other end to the tubular conduit 30. A combination control orifice and plunger mechanism 36 is mounted at the juncture of the tubular conduitsfitl and 32, and is adapted to operatively support the flame stop 10 of the present invention.

Referring now to FIGURE 2, the control orifice and plunger mechanism 36 comprises an orifice housing 38 which defines a central chamber 40' operatively connected through an orifice 42 to a branch passageway 44. Directly adjacent the orifice 42, the housing 38 is formed with an integral sleeve portion 46 adapted to slidably support a plunger 48. The plunger 48 is provided with a reduced section shank portion 50 adapted to be inserted through the-orifice 42 as the plunger 43 is biased inwardly, thereby removing any crankcase residue that may have accumulated within the orifice 42.. A compression spring 52 is provided on the plunger 48 and extends between the sleeve portion 46 of the housing 38 and an enlarged actuating button 54 to resiliently bias the plunger 48 outwardly and maintain it in the position illustrated in FIGURE 2.

In accordance with the present invention, the flame 58 is approximately .0095 inch from its adjacent convolutions.

The coil spring element 56 defines an axially extending central cavity 60 which is closed at the upper end thereof by a closure cap or end plug 62, which plug includes a helically ribbed sleeve portion 64 adapted to be threaded into the upper end of the spring element 56 to secure the closure cap 62 thereto.

As illustrated in FIGURE 2, the lower end portion of the coil spring element 56 is rigidly secured within the tubular conduit 30 by an annular support cup, generally designated 66. The cup 66 is provided with a pair of radially extending flange portions 68 and 70 adapted to respectively engage the lower edge of the spring element 56 and an upper edge 72 of the orifice housing 38 to. operatively secure the spring element 56 thereto.

During normal engine operation, blowby gases are communicated through the conduit 30 in the general direction of the arrow 74%. The gases, upon reaching the flame stop in, flow into the central cavity 60 defined by the coil spring 56 where they pass unimpeded through the interstices between each adjacent convolution 58, as representatively illustrated by the arrows 76. In the event that an induction backfire occurs, the flame pressure front which immediately precedes the backfire and which is herein designated by the dotted arrow 78, strikes the closure cap 62 and compresses the coil spring 56. With the spring 5:) so compressed, the blowby gases, represented by the arrows 76, are prevented from flowing through the interstices between the coils 58, whereby the backfire is effectively extinguished or quenched before it is allowed to propagate into the lower end of the conduit 30 or the passageway 44.

It will be noted that since the coil spring 52 is secured at only the lower end portion thereof, the upper end portion is free to randomly vacillate within the conduit 30 with normal operating vibrations of the engine 12. Such movement of the coil spring 52 substantially eliminates any residue or crankcase contaminants from adhering to the convolutions 58 of the spring 52, or within the interstices therebetween, thus providing a flame stop 10 which is substantially non-clogging and .which there- 3 fore requires very little, if any, maintenance during its entire operational life.

While it will be apparent that the preferred embodiment herein illustrated is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. In a flame stop for a. crankcase ventilation system for an engine, a flow passage,

a compressible wire spring element mounted in said passage, and mounting means for said wire spring element permitting compression of said wire spring element in said passage during crankcase ventilation, said wire spring element being compressible by fluid in said passage at predetermined pressure conditions resulting from engine operation.

2. In a flame stop for a crankcase ventilation system,

a plurality of successive uniform diameter coils of wire defining a central cavity,

said coils being arranged to permit blowby gases to flow axially in to said cavity and to flow out of said cavity by passing unimpeded through the interstices between said coils.

3. A flame stop for a crankcase ventilation system as set forth in claim 1, said wire spring element comprising a plurality of coils wherein said wire spring element is free to move with normal engine vibrations to preclude crank case emissions from accumulating in the interstices of said coils.

4. In a crankcase ventilation system for an engine hava blowby passage extending from the engine crankcase to the air intake system, the invention of a flame stop including a compressible wire spring element' having one end portion rigidly mounted and the other end portion free to vibrate in said passage.

5. In a crankcase ventilation system for an engine hava blowby passage extending from the engine crankcase to the air intake system, the invention of a wire spring element comprising a plurality of successive coils of wire and being closed on one end portion thereof,

said wire spring element having one end portion rigidly secured within said passage and the other end portion free to move with normal engine vibrations.

6. In a crankcase ventilation system for an engine having a blowby passage extending from the engine crankcase to the air intake system, the invention comprising a compressible wire spring element in said passage comprising a plurality of successive uniform diameter coils of wire, and

an end closure plug on said wire spring element,

said wire spring element having one end portion rigidly mounted in said passage and the other end free to move in said passage with normal engine vibrations.

7. In a crankcase ventilation system for an engine having a blowby passage extending from the engine crankcase to the air intake system, and

an orifice and plunger device mounted in said passage,

the invention comprising a flame stop comprising a compressible wire spring element and an end closure plug,

said wire spring element comprising a plurality of successive uniform diameter coils and having one end portion rigidly mounted adjacent said orifice and plunger device, and the other end portion operatively supporting said closure plug and being free to move within said passage with normal engine vibrations.

8. The invention as set forth in claim 7 wherein said wire spring element defines a central cavity into l which blowby gases are permitted to flow, and wherein said successive uniform diameter coils are arranged to permit said blowby gases to flow through the interstices thereof.

9. In a crankcase ventilating system for an engine having a blowby passage extending from the engine to the air intake system, the invention comprising a flame stop comprising a wire spring element and an end closure plug,

said wire spring comprising a plurality of successive uniform diameter coils which are moveable to and from a position precluding induction backflring from propagating through said passage.

10. In a fluid flow passage having an inlet end and an outlet end, said flow passage providing a flow path for fluid from said inlet end to said outlet end under normal conditions, said flow passage being subjected to reverse flow of fluid from said outlet end to said inlet end under abnormal conditions including relatively high pressure, the invention comprising expandible and contractible means, flow passage means integrally formed in said eX- pandible and contractible means having open and closed conditions dependent upon the expanded or contracted state of said expandible and contractible means, and said expandible and contractible means being arranged in said passage to move toward the expanded condition during normal flow and to move toward the contracted condition during abnormal flow.

11. The invention as defined in claim 10 and wherein said expandible and contractible means comprises continuous wire means having a plurality of coils, the distance between adjacent coils of said wire means in the normal expanded condition being sufliciently wide to permit substantially unimpeded flow of fluid from said inlet to said outlet, and the distance between adjacent coils of said wire means and the compressibility of said spring being such that said coils are movable toward one another a sufficient distance as a result of high pressure introduced at the outlet end to restrict passage of undesirable elements from said outlet and to said inlet end.

12. In a fluid transmission system having passage means for fluid under pressure, wire means wound into a plurality of axially extending coils and mounted in said passage means to control flow conditions therein, said coils defining an internal fluid passage, said coils and a surrounding peripheral surface defining an external fluid passage, said coils being spaced from one another a sufiicient distance to permit the free flow of fluid therethrough from one passage to the other passage in one condition, said coils being compressible to limit the free flow of fluid therethrough in another condition, one end of said wire means being restrained relative to the other end of said wire means, and a reaction surface provided at theother end of said wire means to impart axial forces to said wire means from fluid in said passage means sufficient to move said coils under predetermined flow conditions between the one and the other condition.

13. The invention as defined in claim 12 and wherein said coils of said wire means are normally in the one con dition to permit flow through said coils and in said passage in one direction, and said reaction surface extending transversely to flow of fluid in an opposite direction to cause said coils to be compressed and prevent reverse flow through said coils under predetermined pressure conditions.

14. In a fluid system subjected to vibration in use and to contamination by fluids therein, fluid passage means,

smaller than the inside diameter of the surrounding por- References (Iited by the Examiner tion of the fluid passage means to enable movement of UNITED STATES PATENTS said other end of said Wire means due to vibration sufficient to flex and compress said coils to clear said plui z ih g rality of flow paths of contamination and maintain said 5 2686504 8/54 1c Paths an 2,906,252 9/59 Beardsley 123 119 15. The rnventlon as defined in claim 14 and whereln 3,030,942 4/62 Thompson 123 119 a mass is mounted on the other end of said wire means increasing the moment of inertia thereof and fiexure and RICHARD WILKINSON Examinercompression thereof due to vibration. 10 KARL J. ALBRECHT, Examiner. 

1. IN A FLAME STOP FOR A CRANKCASE VENTILATION SYSTEM FOR AN ENGINE, A FLOW PASSAGE, A COMPRESSIBLE WIRE SPRING ELEMENT MOUNTED IN SAID PASSAGE, AND MOUNTING MEANS FOR SAID WIRE SPRING ELEMENT PERMITTING COMPRESSION OF SAID WIRE SPRING ELEMENT IN SAID PASSAGE DURING CRANKCASE VENTILATION, 